Sorry to bother you again but I need some advice. After having wormed my tank with wormer plus a couple two weeks ago, fixing my hydra problem, I have now come across another creature in my tank which I'm concerned about.

It is thin and torpedo shaped (it's surface looks like a shell or exoskeleton) and it moves on legs which I can't see but it's apparent by how fast it moves. It can move very fast and hangs out on anything from caves, to wood, to the sides of the glass. It does not appear to be interested in the zebras that I've seen.

I'm very worried about this as whatever it is managed to survive wormer plus. What is this creature? Are they harmful? If so, how can I fully remove them?

They do scoot around really fast but don't jump so much as scurry if you know what I mean. I've always associated the term water fleas with daphnia, these are of a similar size but don't jump at all like daphnia do. Could it be a different form of water flea?

I don't mind them being there as long as they aren't a risk to my zebs. I'm a bit confused as to why the zebs aren't trying to eat them. Thanks for your quick reply and I'm feeling optimistic that these little creatures will be safe for my zebs.

Just an update, I've been having a look about trying to figure out what these guys are. Could it be possible that they are ostracods? These little things have a hardened shell which is hinged in the dorsal region (resulting in the thin torpedo shaped I've seen), they are resistant to medication because of this shell (hence the wormer plus survival) and fish don't eat them again because of the shell. If they are these ostracods, are they fish-safe?

I'm not sure of this so please feel free to tell me I'm wrong as I just want to be sure my fish are safe.

Hi Linzi,
no idea what these are however, from experience, critters with exosceleton are really difficult to get rid off. I would suggest using Parazin P - it is safe for the fish and does a good job on unwanted visitors. The treatment takes around 40 days because it attacks the critters when they shed their shell to get new one - that is when they are susceptible to it. Given the various stages of development of these critters it is recommended to have a long treatment period to eradicate the lot.

If you are worried about them, a way to control the population until the medication gets rid of the rest is to take the wood, caves and every removable tank ornament (furniture) and put it for 30 seconds in the microwave. The microwaves will blast out the lot of them (make sure there is no fry hiding in crevices.

They look very like what I have in my tanks. They too seem to be in the wood. No harm seems to come to anything although annoying to see them LOL I even have them get into the fry savers with fry but no harm comes of them. Be interesting to know if you manage to get rid of them

They really don't seem to be bothering my zebs at all. I recently added a large female (I hope!) and since then they've started disappearing, so I guess she might have a taste for them...I'm thinking of adding a shoal of tetra and some red cherry shrimp to the tank and I'm guessing they might help keep the numbers down between them. I have been resisting doing this just yet as I know there have been a lot of differing opinions on zeb tankmates!

I was thinking of the microwave trick but unfortunately the wood I have in there is larger than my microwave. It's a real shame that wood isn't sold in a pre-treated, parasite free way. I think there's a real market for a company selling aquarium wood which has been pre-soaked and microwaved so it's safe. Anyone want to go into business?!? lol

Hi
Not sure why anybody has not mentioned before but if wood does not fit in the microwave why not put it in the oven?.
In this case I would expect you only have to get the wood to a few degrees above the tanks heat maybe worth a go better than nothing.

Just a thought.

Jerry

Caution is a most valuable asset in fish keeping, especially if you are the fish.

That's an excellent idea, I've got some more wood I'm soaking at the minute that I can test this on. I'm guessing they'd have to stay in longer than a microwave as the heating will be much more gradual...